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also: VMS and OVMS


    VMS is a high performance operating system made by DEC that runs on DEC VAX. OpenVMS is an updated version of VMS and runs on both the DEC VAX and the DEC Alpha.


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    “VMS and OpenVMS are the same operating system under two different names (the name changed to OpenVMS about the time POSIX support and a few other “open” items were added.)” — Joshua Copee53

    “OpenVMS, originally called VMS (Virtual Memory System), was first conceived in 1976 as a new operating system for Digital's new, 32-bit, virtual memory line of computers, eventually named VAX (Virtual Address eXtension). The first VAX model, the 11/780, was code-named “Star”, hence the code name for the VMS operating system, “Starlet”, a name that remains to this day the name for the system library files (STARLET.OLB, etc.). VMS version X0.5 was the first released to customers, in support of the hardware beta test of the VAX-11/780, in 1977. VAX/VMS Version V1.0 shipped in 1978, along with the first revenue-ship 11/780s.”w41

    “OpenVMS was designed entirely within Digital Equipment Corporation. The principal designers were Dave Cutler and Dick Hustvedt. OpenVMS was conceived as a 32-bit, virtual memory successor to Digital’s RSX-11M operating system for the PDP-11. Many of the original designers and programmers of OpenVMS had worked previously on RSX-11M, and many concepts from RSX-11M were carried over to OpenVMS.”w41

    “OpenVMS is a 32-bit, multitasking, multiprocessing virtual memory operating system. Current implementations run on Digital’s VAX and Alpha computer systems.”w41

Intended purpose

server/mainframe: medium to large scale servers; minicomputers; mainframes

desktop/workstation: workstations (for those with command line familiarity)

handheld: not appropriate

real time: not appropriate

Kind of OS: proprietary

    “In the trade press, a Digital employee was once quoted as saying that OpenVMS could now pass the X/OPEN UNIX branding tests. But until it has been certified it can not be called a UNIX.” —John Malmberge85

    “Unless an operating system has officially passed the X/OPEN UNIX branding, it can not be considered a UNIX. It can only be considered to be UNIX like or compatible. Because UNIX is a registered trademark of X/OPEN, this is a legal issue. In trademark law, the owner of a trademark must prosecute any known generic use of their trademark or they can lose their trademark. I know it seems petty, but that is the way the U.S. legal system works.” —John Malmberge85

Release Date: 1978e62

Current Version: OpenVMS 7.2-1e110


    “For HOBBY use, all version of OpenVMS/VAX are now available for free use by DECUS members. DECUS membership is also free. At this time [a hobby version of] OpenVMS/ALPHA is not available.” —John Malmberge85

    “The actual cost of a VMS license is variable based on your quantity discount from your vendor and the class of the hardware it is to run on. Since it is normally bundled with a hardware purchase, the best way to derive it is to get a quote from Compaq for a system with VMS and then the same system with Windows-NT server or workstation.” —John Malmberge85

    “Prices for OpenVMS/Alpha systems appear to start at about $3,700. This could be subject to change if Compaq reacts to market pressures.” —John Malmberge85

Hardware Supported:

    “OpenVMS runs on Alpha and VAX processors” — Joshua Copee53

    “O-VMS should run on any of the VAXen, including MicroVAX, VAXStation, and VAXServer after the MicroVAX 1.” — Bruce Lanee51

    Performance information about Digital products: www.compaq.com/alphaserver/download/alphaserver_gs_benchmark_performance_v2.pdf

    VAX-11 assembly language is discussed in the assembly language section.

Maximum Number of Processors: 32e120

    “16 processors within one system (SMP) — Compaq AlphaServer GS160; Up to 96 systems in a VMScluster, using various interconnects, including: Ethernet, FDDI (and DS3/T3 through bridging), SCSI, DSSI (Digital Storage Systems Interconnect), CI (Cluster Interconnect), Fibre Channel, SMCI (Shared Memory Cluster Interconnect)” — Joshua Copee111

    “Compaq’s OpenVMS OS currently supports 32 processors in a single system, not 16 (however, a lot of NUMA-awareness tweaking has yet to be done to render this an efficient use of resources).” —Terry C. Shannone120

Number of bits: 64 bits (OpenVMS Alpha); 32 bits (OpenVMS VAX)e111

Kernel: proprietary

POSIX: compatiblee53


File Systems Supported:

    “OpenVMS with the NAS packages that are bundled with new systems, has full connectivity with TCP/IP protocols. While the NAS package is technically an add-on, at least a base level system is included with all systems sold in the past few years. This provides DECNET IV, DECNET PLUS (OSI PROTOCOL STACK), TCP/IP (FTP, NFS, …) and others. OpenVMS with the NAS packages also supports X-11 and MOTIF. Commercial and freeware packages are available to communicate with SMB protocols.” —John Malmberge85

    “The file systems natively supported are ODS-1, ODS-2, and ISO-9660. Commercial and freeware programs are available for reading and writing FAT floppy disks.” —John Malmberge85

    “Underneath the file system OpenVMS supports Record Management Services or RMS. RMS allows programs to support many different file organizations easily and transparently to programs. Other operating systems do not provide this functionality, requiring more work for the programmer, or a small database product to be used.” —John Malmberge85

Other Systems Emulated:

Graphics Engine:

Text Command Shell: DCLe85

    “While the view from the DCL shell is different from UNIX compatible systems, there is much in common between the two operating systems. As such, it would be rare to find a feature in one of the OpenVMS that is not in a UNIX compatible and vicea-versa. The actual name it goes by could be quite different. There are however some that should be taken into consideration.” —John Malmberge85

User Interface (graphic): X Window X-11e85 and Motife85

Graphic Command Shell:

    “OpenVMS with the NAS packages (bundled with new systems) also supports X-11 and MOTIF.” —John Malmberge85

Disabled support:

Internet Services:

    “Most LINUX E-MAIL packages are available for OpenVMS, and the Operating System contains an easy to use E-MAIL system that can be used for both internal and Internet E-MAIL.” —John Malmberge85

Application Programs:




references within this web site

(for your convenience, look for this symbol marking passages about VMS and OpenVMS)

further reading: web sites

Please send recommendations on additional URLs to Milo.

official web sites


    http://www.digital.com/info/SP2501/ “OpenVMS Operating System for Alpha and VAX, Version 7.1”e53

    http://www.openvms.compaq.com:8000/index.html “OpenVMS documentation website”e110


(Frequently Asked Questions)



    ftp://ftp.digital.com/pub/Digital/dec-faq/decinfo “DEC general FAQ”

user group web sites

    http://www.levitte.org/~ava/vms_decus.htmlx (DECUS)e7

    http://www.levitte.org/~ava/vms_forum.htmlx (news groups)e7

other related web sites



    Stokely’s DEC System Administrator FAQ links

further reading: books

If you want your book reviewed, please send a copy to: Milo, POB 1361, Tustin, CA 92781, USA.

Price listings are for courtesy purposes only and may be changed by the referenced businesses at any time without notice.

further reading: books: introductory/general

    VMS User’s Guide (Digital Press Vax Users Series); by James F. Peters, Patrick Holmay; Digital Press; January 1990; ISBN 1555580149; paperback; 304 pages; $39.95

    Open VMS Operating System Concepts; 2nd edition; by David Donald Miller; Digital Press; February 1997; ISBN 1555581579; paperback; 550 pages; $44.95

    Unix for VMS Users (Digital Press Vax Users Series); reprint edition; by Philip E. Bourne; Digital Press; February 1994; ISBN 1555580343; paperback; 368 pages; $39.95

further reading: books: administration

    Open VMS System Management Guide; by Lawrence L. Baldwin Jr.; Digital Press; September 1995; ISBN 1555581439; paperback (with disk); 432 pages; $54.95

    VAX/VMS: Writing Real Programs in DCL (Digital Press Vax Users Series); by Paul C. Anagnostoplulos, Paul G. Anagnostopoulos; Digital Press; January 1991; ISBN 1555580238; paperback; 409 pages; $42.95

further reading: books: internet

further reading: books: enterprise/business

further reading: books: content creation

further reading: books: programming

    Software Implementation Techniques: Writing Software in OpenVMS, OS/2, Unix, and Windows NT; 2nd edition; by Donald E. Merusi; Digital Press; November 1995; ISBN 155558134X; paperback; 567 pages; $52.95

further reading: books: hardware

further reading: books: miscellaneous

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If you want your book reviewed, please send a copy to: Milo, POB 1361, Tustin, CA 92781, USA.

geek humor

    “Infinity is not part of the VAX architecture.” —Jason Downs

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    If you have an extra or unwanted copy of any official manuals or documentation on this operating system, please send them to: Milo, POB 1361, Tustin, CA 92781, USA. I have the following items: NONE.

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    Last Updated: February 14, 2002

    Created: June 22, 1998

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